In recent years, projector devices have been widely known as a projection type image display device that displays a projection image on a projection surface such as a screen or the like. Specifically, in recent years, there has been a growing demand for ultra-wide-angle front projection type projector devices capable of displaying wide-screen images while narrowing a projection space. The ultra-wide-angle front projection type projector device is capable of setting a focal length of a projection image at a short range (hereinafter, such a projector device may be referred to as a “short focus projector device”). In the case of using the short focus projector device, it is possible to display a wide-screen image in a limited space by projecting the wide-angle image obliquely with respect to a projection surface.
In general, the projector device is used after adjusting a projection image quality to an optimum state when installing the projector device or changing a screen size, for example. Patent Literature 1 listed below describes that a projected image from an ultra-short range projector (short focus projector device) is especially sensitive to small positioning adjustments of a projector installing position. Therefore, Patent Literature 1 discloses a technology for identifying information to facilitate adjusting the position of a projector.